[pgpool-general: 3248] Replication through pgpool

[Marco Nietz]

Hi,

i have the following setup that causes some problems.

Two database-machines, both running postgresql 9.3.5 and pgpool 3.3.3 on 
debian wheezy 7.7

Because i don't have an internal network (or second network card) 
between the two systems i'm forced to do the streaming replication over 
a pgpool connection like a normal client connection.

So on db1 (master), postgres is bound on localhost:6432 and pgpool is 
bound on the public interface using port 5432. db2 (slave) connects to 
db1 using port 5432 (pgpool).

My first question is, if such a setup should be possible at all 
(nevertheless if it's advisable or not) ?

The initial base backup is very slow but succefull, also connecting db2 
to db1 is working for some time (pg_stat_replication). But then, after 
some time the replication lags grows and no more transactions will be 
streamed to the slave. During this time i see the Tcp receive windows 
filling up on db1 using netstat. Restarting pgpool on the master solves 
the problem. One of the connections from the slave to the master stays 
in status START_REPLICATION.


Kind Regards
Marco